GENUS SALPINGCECA. 



345 



pristine contour, and developing a new hyaline collar and flagellum, is not to be dis- 

 tinguished from the ordinary zooids with which it is associated. That portion of 

 the sarcode which is extruded and breaks away in the manner just described, is 

 found in the case of the species now under discussion, to uniformly assume a persis- 

 tent and highly characteristic shape. This, as shown at PI. V. Figs. 8 and 9, may be 

 compared to that of a minute, stellate, free-swimming Amoeba corresponding closely 

 with the type described by Dujardin under the title of Amceba radiosa, but of much 

 smaller comparative proportions and with shorter pseudopodia. In close proximity 

 to the larger colonies of this species, minute, floating, stellate, amoeboid zooids, 

 identical in form with those whose detachment has been actually observed, are 

 almost invariably met with, these at the same time retaining a marked resem- 

 blance to the phase assumed by the sarcode when issuing from the lorica as shown 

 at Fig. 7, allowing for that slight contraction and general pulling together of its sub- 

 stance which ensue upon its detachment from the parent mass. 



Professor James-Clark, in his original account of this species, attributes to it a 

 distinct oral and anal aperture, lying somewhere near the base of the flagellum. 

 This interpretation of its alimentary apparatus has, however, as in the case of all 

 other members of the Choano-Flagellata, to be finitely dismissed. Carmine, when 

 administered, was intercepted and ingested under circumstances and in a manner 

 absolutely identical with what has been already described at page 326 of Monosiga 

 gradlis, while digested particles were observed to pass out in a similar manner 

 from any part of the area confined by the base of the hyaline collar. Professor 

 Clark further describes the flagellum as usually assuming a rigid and arcuate deport- 

 ment ; this aspect, however, is only the optical impression imparted at first sight 

 through its exceedingly rapid revolution, an explanation which is satisfactorily con- 

 firmed by introducing carmine and watching the course of the currents produced 

 in the manner already detailed. The duration of time occupied between the systole 

 and diastole of each of the three or four conspicuous contractile vesicles situated at 

 the lower extremity of this animalcule's body, average, in accordance with the 

 author's observations, from thirty to fifty seconds. The duration of time between 

 the expansion and contraction of these special vesicles, appears to differ consider- 

 ably among allied members of the same genus, and furnishes probably a supplementary 

 character for specific diagnosis. 



While inspecting the manuscript note-books kindly placed at the author's disposal 

 by Mr. Carter, a drawing has been noticed which beyond doubt represents several 

 examples of a species closely allied to the present one, though, so far as can be judged 

 from the comparatively low power of magnification employed in their delineation, 

 the necks of the loricae would appear, proportionately, to be considerably shorter. 

 The drawing quoted, indicating by the short diverging lines at the apex of each lorica 

 the presence of the characteristic collar and central flagellum, is with Mr. Carter's 

 permission reproduced at PL III. Fig. i. Beyond the registration of their having 

 been obtained from fresh water at Bombay in the year 1855, no written details are 

 preserved. The Chytridium ampullaceum of Braun * presents a remarkable super- 

 ficial resemblance in both form and habits of growth to the minute Flagellate type 

 now under discussion. No trace, however, of the flagellum or collar-like appendage, as 

 distinctly marked in the preceding instance, is exhibited in the illustrations quoted, 

 but merely a short conical projection beyond the orifice of the flask-shaped lorica, 

 somewhat resembling a minute pseudopodic protrusion, but which may at the same 

 time be the conical operculum of a genuine Chytridium. Stein, in his recently 

 published volume,! appears inclined to identify the present form with Braun's type, 

 and at the same time associates with the title of Salpingoeca amphoridium an elongate 

 form altogether distinct from the one originally figured and described by Professor 

 H. James-Clark. Upon this more elongate type the author has consequently con- 

 ferred in this volume the new name of Salpingoeca Steinii. None of the various 

 polymorphic phases of the present species, as here figured and described, appear 

 to have been noted by Professor Stein. 



* 'Abhl. Berl. Akad.,' Taf. v. figs. 24-26, 1855. f 'Infusionsthiere,' Abth. iii., 1878. 



